Analyzing and Resolving Over-Constrained or Inconsistent Sketches
In evaluating geometry, the system considers the degree of freedom that it has. In two dimensions, points and lines have two degrees of freedom, circles have three and ellipses have five degrees of freedom. Fixed geometry will never be moved by the system, and has no degree of freedom.
If all of the degrees of freedom of a geometry have been taken up by a consistent combination of dimensions and fixed geometry, that geometry is said to be iso-constrained (also known as well-defined). Geometry that still has some degrees of freedom is said to be under-constrained (also known as under-defined).
Status codes are given through a graphical way (colors) during the Sketch edition. The update error dialog box when returning in 3D explicitly gives them (check visualization of diagnosis in Tools > Options > Sketcher > Colors).
Note:
The system will mark all entities that are relevant to a problem
rather than just the first item encountered. So, for instance, in
the case of an inconsistent triangle with sides 10, 10 and 50, all
three dimensions would be marked as INCONSISTENT.
The order in which the codes are listed below is significant. The
system will test to see whether a geometry should have the status
OVER-CONSTRAINED before considering whether it should be
INCONSISTENT.
This chapter describes the over-constrained and inconsistent status codes calculated by the system and explains methods for solving any underlying problems with a sketch.